Chain saw



FIG. 1 is a perspective right view of a chain saw;

FIG. 2 is a perspective left view of a chain saw;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines shown in the drawings represent portions of the chainsaw that form no part of the claimed design.

CLAIM The ornamental design for a chain saw, as shown and described.